Sheet-metal pipe.



BIRNBAUM. SHEET METAL PIPE. APPLICATION FILED FEB. a, 1910.

Patented Nov, 15, .1910.

IIWEIVTOR WITNESSES.

W a W m h crrn sra'rns pggniu ricn.

, HENRY BIRNBAUM, OF RAPID .CI'IY, SOUTH DAKOTA.

SHEET-METAL PIPE.

T 0 a t whom it may concern:

Be it, knownlthat I, HENRY BIRNBAUM,

a citizen of the United States, and a resident ofRapid City, in the county of Pennington and State of South Dakota, have invented an Improvement in Sheet-Metal Pipes, of which the following is a specification. I have devised a sheet-metal pipe-section adapted to serve as a stovepipe, or for various other uses, and which is so constructed that it may be enlarged or contracted in diameter to accommodate and receive other sections differing in size, and the aggregate length of two or more sections thus coupledmay be increased or reduced by sliding one upon the other, telescopically, as hereinafter described.

The details of cmistruction, arrangement, and COll'lbllltltlOl] of parts are illustrated in the accompanying drawing, in which Figure l is a pcrs wctivc view of a stovepipe section constructed in accordance with my invention. Fig. 2 is a plan view of the main portion of such section with the locking or fastening strip partly applied. Fig. 3 is a plan view of the pipe scction without the locking strip, thc longitudinal edges of the divided pipe being shown separated. Fig. t is a cross section on the line i-l of Fig. 2. Fig. 5 is a similar section on the line 55 of Fig. 2 showing the locking strip in position. Fig. (5 is a perspective view of a portion of the locking strip. Fig. 7 is a plan View of a portion of the blank from which the body of a pipe-section is formed.

Instead of the longitudinal edges of a pipe-section being pcriuancntly connected, as usual in the construction of stovepipc and other sheet-metal pipe, 1 construct and adapt them for detachable connection, for purposes hereinafter stated. in Fig. 1, which shows a complete stovepipe section, one end is contracted and corrugated, as usual, and the other end 1 is plain, that is to say, is neither corrugated nor ('Qlll'l'tN'lttl. As shown in Figs. 2 and 3, the ltnigitudinal edges of thc pipe-section are provided with hooks .2 and 3, there being preferably two pairs of the former and a single pair of the latter, which is located at or adjacent to the plain endof the piposcction. 'lhc hooks are formed by slitting the metal transversely and bending backward the portions thus separated in part lrom thc body. The hooks 2 and 3 ditl'cr in construction. In the case of the former, the edges of opposite hooks Specification of Letters Patent. Patented N 15, 1910,

Application filed February a,

1910. Serial No. 542,816.

are parallel, while in the case of the latter (3), the edges are inclined inward from the outer end of the pipe-section.

The locking strip 4; is formed preferably of the same material as the body of the pipesection, that is to say, of thin sheet metal, a narrow strip of the latter being cut out and its edges curved inward, as shown in Fi 6, a space being left, beneath the flanges 5, t us formed, which is adapted to receive the hooks 2 and 8, as will be understood by reference to Fig. 2, Where the locking stri 4 is shown, by full lines, enga ed with the rst pair of hooks 2, and, by dotted lines, engaged with the inclined or camhooks 3; that 1s to say, the width of the strip 4 is such that it has a wedging action with the books 3, whereby, when the strip 4: is pushed firmly 1 into the position indicated by dotted lines,

Fig. 2, it is held in firm frictional engagement with the hooks 3. By employing locking strips of different widths, it is apparent that the longitudinal edges of the pipe-section may be separated more or less, thus in-. creasing its diameter if occasion requires, and adapting it for telescopic connection with another pipe-section. In such case, in

order to avoid an open gap between the ad-' jacent edges 5, 5, of the pipe-section, I construct one of them, to wit, the edge 5, with an underlying extension or flap 6 which is formed by curving the edge 5* backward and then reversely, or toward the opposite edge 5, as will be understood by reference to Figs. 3, 4, and 5. I thus produce not only the extension flap 6, which, in practice, extends under the opposite edge 5 when the pipe-section is closed, but forms, with the overlying part or edge 5 of the body section, a recess adapted to receive the opposite edge 5 of the body section, as shown in Fig. 4.

In Fig. 7, I illustrate a sheet-metal blank from which a body section is formed, the same being shown slitted at the proper places to form hooks 2 and 3, before described.

It will be seen that, by the construction and combination of parts above described, I produce a pipe-section adapted to be enlarged in diameter as required for nesting a series of sections, for convenience and economy of storage and transportation, or enlarged at one end as required for telescopic engagement with pipes differing from it in diameter. In the latter case, the locking strip 4 will be pushed on or over the cam hooks 3 wholly. or partly, according to the spread or diameter required at the plain end 1 of the pipe-section. That is to say, under normal conditions, when a considerable length of pipe is made up of a series of sec tions similar in construction, the contracted end of one willbe inserted in the plain end of the other, and the locking strip 4 may then be adjusted as shown in Fig. 1; but, in case of a difference of diameter between pipe sections, the locking strip may require to be adjusted as shown by dotted lines in Fi 2. In case of employing aseries of loc 'ing str'ps differing in width, it is obvious that the extension flap 6, before described, will come into play, since it will then project under the opposite edge 5 of the pipe-section, and said edge will overlie it, Without, however, entering the socket, as indicated in Fig. 4. The inner end of the locking strip 4 may be provided with an opening for attachment of a pull-wire or for insertion of a tool or device for sliding it on or off the hooks.

ing its edges curved inward What I claim is A stove-pipe section having one end contracted for telescopic engagement with another section and its opposite end made of slightly greater diameter, one of the longitudinal edges being bent backward and then reversely, thus forming an underlying flap adapted when the section is closed to extend under the opposite edge, the body of said section being provided with oppositely disposed hooks along its longitudinal edges and other hooks 3 located at the larger end of the section, their edges being inclinedso as to diverge toward the said larger end of the section, and a locking device adapted for sliding engagement with all the hooks, the same consistlng of a sheet metal strip havand arranged at apart, as shown and de HEi R Y [HR N BA UM.

a uniform distance scribed.

lVitnesses E'rnnn ALLEN, I. M. PICKE'IT. 

